Stewart Poirier, 53, showed no emotion as his sentence was read by Justice Rebecca Rutherford in a downtown Toronto courtroom Friday.

Poirier has pleaded guilty to the arson of the Yonge Street heritage building and setting other fires, including at a Toronto Community Housing Corporation property on Sackville Street in the east end.

The judge described the case as tragic, saying Poirier had a long history of mental illness and a horrendous upbringing. His father was an abusive alcoholic, court has heard.

He was institutionalized at age seven and was physically and sexually abused at the mental health facility in which he spent many years. A forensic neuroscientist testified he has the mind of a child and a personality disorder that includes pyromania.

He is violent, addicted to drugs and enjoyed seeing people suffer, court heard. When he admitted to setting fire at the Empress Hotel, he was already on probation for arson.

Rutherford said he is a danger to the public, and that is why he must serve a lengthy sentence.

The six-alarm blaze at the site of the former Empress Hotel at 335 Yonge St. started at around 4 a.m. ET on Jan. 3, 2011. It took at least four hours to bring the fire under control, and firefighters were still hosing the building down at noon that day.

The building had to be demolished after the fire, leaving several tenants without a home, including the popular Salad King restaurant that has since relocated to the other side of Yonge Street.